driving

The enactment of adult use marijuana regulation in Colorado and Washington is not independently linked to an increase in traffic fatalities, according to a study published this week by the National Bureau of Economic Research.

Investigators at the University of Oregon compared traffic accident outcomes in Colorado and Washington following legalization to other states with similar pre-legalization economic and traffic trends. They reported, “We find that states that legalized marijuana have not experienced significantly different rates of marijuana- or alcohol-related traffic fatalities relative to their synthetic controls.”

Authors concluded, “In summary, the similar trajectory of traffic fatalities in Washington and Colorado relative to their synthetic control counterparts yield little evidence that the total rate of traffic fatalities has increased significantly as a consequence of recreational marijuana legalization.”

The study’s findings are similar to those of a 2017 study published in The American Journal of Public Health which reported, “Three years after recreational marijuana legalization, changes in motor vehicle crash fatality rates for Washington and Colorado were not statistically different from those in similar states without recreational marijuana legalization.”

A 2016 study reported that the enactment of medical cannabis legislation is associated with an immediate decline in traffic fatalities among younger drivers.

Full text of the study, “Early evidence on recreational marijuana legalization and traffic fatalities” is available from the National Bureau of Economic Research. NORML’s fact-sheets on cannabis, psychomotor performance, and accident risk is online here.

Standard roadside field sobriety tests (FST) are not reliable indicators of marijuana-induced impairment, according to a ruling by the Massachusetts Supreme Court.

Justices determined that there is a lack of scientific consensus as to the validity of FSTs for determining whether a subject is under the influence of cannabis. They opined: “There is ongoing disagreement among scientists, however, as to whether the FSTs are indicative of marijuana impairment. In recent years, numerous studies have been conducted in an effort to determine whether a person’s performance on the FST is a reliable indicator of impairment by marijuana. These studies have produced mixed results. … We are not persuaded … that the FSTs can be treated as scientific tests establishing impairment as a result of marijuana consumption.”

As a result, justices ruled that police may only provide limited testimony with regard to a defendant’s FST performance. An officer “may not suggest … on direct examination that an individual’s performance on an FST established that the individual was under the influence of marijuana,” the court determined. “Likewise, an officer may not testify that a defendant ‘passed’ or ‘failed’ any FST, as this language improperly implies that the FST is a definitive test of marijuana use or impairment.”

The court further ruled that a police officer may not testify “without being qualified as an expert [as] to the effects of marijuana consumption [or] offer an opinion that a defendant was intoxicated by marijuana [because] no such general knowledge exists as to the physical or mental effects of marijuana consumption, which vary greatly amongst individuals.”

Attorneys Steven Epstein and Marvin Cable filed an amicus curiae brief in the case on behalf of national NORML.

The enactment of statewide laws regulating the adult use and sale of cannabis is not associated with subsequent changes in traffic fatality rates, according to an analysis of traffic safety data (“Crash fatality rates after recreational marijuana legalization in Washington and Colorado”) published today in the American Journal of Public Health.

Investigators from the University of Texas-Austin evaluated crash fatality rates in Colorado and Washington pre- and post-legalization. They compared these rates to those of eight control states that had not enacted any significant changes in their marijuana laws.

“We found no significant association between recreational marijuana legalization in Washington and Colorado and subsequent changes in motor vehicle fatality rates in the first three years after recreational marijuana legalization,” author concluded.

They further reported, “[W]e also found no association between recreational marijuana legalization and total crash rates when analyzing available state-reported nonfatal crash statistics.”

Commenting on the findings, NORML Deputy Director Paul Armentano said: “These conclusions ought to be reassuring to lawmakers and those in the public who have concerns that regulating adult marijuana use may inadvertently jeopardize public safety. These results indicate that such fears have not come to fruition, and that such concerns ought not to unduly influence legislators or voters in other jurisdictions that are considering legalizing cannabis.”

A prior study published last year by the same journal reported that the enactment of medical marijuana legalization laws is associated with a reduction in traffic fatalities compared to other states, particularly among younger drivers.

Fatal accident rates have fallen significantly over the past two decades — during the same time that a majority of US states have legalized marijuana for either medical or social use. In 1996, the US National Highway Traffic Safety Administration reported that there were an estimated 37,500 fatal car crashes on US roadways. This total fell to under 30,000 by 2014.

A summary of the study appears online under ‘First Look’ on the apha.org website here.

The passage of medical marijuana legalization is associated with reduced traffic fatalities among younger drivers, according to data published online ahead of print in the American Journal of Public Health.

Investigators from Columbia University in New York and the University of California at Davis analyzed traffic fatality data from the years 1985 to 2014.

They reported that states with medical cannabis laws had lower overall traffic fatality rates compared to states where cannabis is illegal, and that there was an immediate decline in motor vehicle deaths following the establishment of a legal cannabis market – particularly among those under 44 years of age.

Authors concluded: “[O]n average, MMLs (medical marijuana laws) states had lower traffic fatality rates than non-MML states. …. MMLs are associated with reductions in traffic fatalities, particularly pronounced among those aged 25 to 44 years. … It is possible that this is related to lower alcohol-impaired driving behavior in MML-states.”

An abstract of the study, “US traffic fatalities, 1985-2014, and their relationship to medical marijuana laws,” appears online here.

Per se driving limits for the presence of THC are arbitrary and may improperly classify motorists who are not behaviorally impaired, according to the findings of a study published today by the American Automobile Association (AAA) Foundation for Traffic Safety.

Per se driving limits criminalize the act of operating a motor vehicle if the driver possesses detectable amounts of specific drugs or drug metabolites above a set threshold. Under these laws, drivers are guilty per se of violating the traffic safety laws even absent evidence of demonstrable behavioral impairment.

Five states – Montana, Nevada, Ohio, Pennsylvania, and Washington – presently impose per se limits for the detection of specific amounts of THC in blood while eleven states (Arizona, Delaware, Georgia, Illinois, Indiana, Iowa, Michigan, Oklahoma, Rhode Island, Utah, and Wisconsin) impose zero tolerant per se standards. In Colorado, the presence of THC in blood above 5ng/ml “gives rise to permissible inference that the defendant was under the influence.” Legislation similar to Colorado’s law is presently pending in California.

The Automobile Association’s finding is similar to that of the US National Highway Traffic Safety Administration, which acknowledges: “It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects. … It is inadvisable to try and predict effects based on blood THC concentrations alone.”

NORML has long articulated a similar opposition to the imposition of per se driving thresholds for THC and/or its metabolites, stating, “[R]ecently adopted statewide per se limits and zero tolerant per se thresholds in the United States criminally prohibiting the operation of a motor vehicle by persons with the trace presence of cannabinoids or cannabinoid metabolites in their blood or urine are not based upon scientific evidence or consensus. … [T]he enforcement of these strict liability standards risks inappropriately convicting unimpaired subjects of traffic safety violations, including those persons who are consuming cannabis legally in accordance with other state statutes.”